Update Debian kernel to 5.7.6

.github/workflows/debian.yml

@@ -7,8 +7,8 @@ name: Debian
 
 env:
   GPG_KEY_ID: 56C464BAAC421453
-  KERNEL_VERSION: 5.7.5
-  KDEB_PKGVERSION: 5.7.5-1
+  KERNEL_VERSION: 5.7.6
+  KDEB_PKGVERSION: 5.7.6-1
   LOCALVERSION: -surface
   MAINLINE_REPO: git://git.launchpad.net/~ubuntu-kernel-test/ubuntu/+source/linux/+git/mainline-crack
   MAINLINE_BRANCH: cod/mainline